1. Field of the Invention
The present invention relates to a flash unit, a camera, and a camera flash system, and in detail relates to a flash unit that can be used as a supplementary lighting device for a camera such as an imaging device, and that is capable of being used while being attached to a camera or when detached from the camera, to a camera capable of operating in cooperation with this flash unit, and to a camera flash system comprising this flash unit and camera.
2. Description of the Related Art
When taking photographs using supplementary light of a flash unit, it is necessary to take into consideration the area illuminated by the flash unit when taking photographs. In particular, in the case where the flash unit is arranged at a positioned apart from the camera, illumination conditions of a subject vary depending on the position of the flash unit and the direction of a light emitting section, and so the setting of the flash unit is important when taking photographs. There have therefore been various proposals for strobe systems that are capable of confirming the illumination conditions achieved by the flash unit before taking a picture.
For example, Japanese publication of unexamined application No. 2000-89305 (Laid-open Mar. 31, 2000) discloses a strobe system that also emits preflashes from a slave strobe in response to flash emission from a master strobe, and controls flash intensity of the master strobe and the slave strobe from a ratio between amount of reflected light at the time of preflash and a set flash intensity. Specifically, in this prior art it is possible to confirm lighting achieved by a flash unit that has been is arranged away from the camera using modeling flash.